1. Field of the Invention
This invention relates generally to orthotic devices, and more particularly, to an orthotic device for use in rehabilitating individuals suffering from muscle spasticity, hypertonicity, and contractures which may be caused by stroke or brain injury.
2. Description of the Related Art
Patients with neurological disorders often suffer from muscle spasticity, hypertonicity and contractures which are usually caused by damages to the systems that control voluntary movements. Spasticity and hypertonicity are demonstrated when muscles receive improper nerve signals causing them to contract and become shortened. Improper control of brain signals is often due to damage within the brain caused by stroke, brain injury, or other traumas.
Contracture is one of the most detrimental consequences of spasticity or hypertonicity. Contractures are generally due to shortening of muscle fibers and other soft tissues and structural changes. When a muscle is not regularly put through its full range of movement, it can shorten and result in an abnormal condition including abnormal joint posture. This makes stretching the muscle difficult and may set up a vicious cycle of even more shortening and decreased stretch. The end result of untreated contracture is a long-term, often painful, abnormal posture, such as over-flexion of the hand or inversion of the foot.
One primary type of treatment for muscle spasticity, hypertonicity and contractures is regular stretching exercises including lengthening of flexors prescribed by a physical and occupational therapist. Early on in contracture development, range of motion exercises can help prevent permanent tendon shortening. Treatments for the upper extremities typically also include using a splint to position the patient's hand and wrist in a manner so as to keep them in a position that maintains range. The splint usually has a hand support contoured in the shape of the patient's hand in which the fingers are partially flexed and the wrist is extended. The hand support typically includes an interior surface or padding that directly contacts substantially the entire interior side of the hand, including the arch region. As such, the hand may be in a power position to flex on an object, which in turn can trigger more finger and thumb flexion. Thus, the occurrence of contractures may actually increase when the patient wears most conventional splints intended to reduce and manage the contractures.
In view of the foregoing, there is a need for an improved orthotic device and method for treating patients with muscle spasticity, hypertonicity and contractures. To this end, there is a particular need for an orthotic device and approach of treatment that reduces the occurrence of muscle over-activity while at the same time reverses muscle and tendon contractures.